Order of Battle Quirkiness

I'm having a bit of a time sorting out the order of battle for my Legions Imperalis World Eater's force. In case you hadn't noticed, I'm kind of a dork. As part of that I'm kinda fixated on organization of my armies. I really try to be as true to the fluff as possible and it's tricky. Yeah, part of that is that Games Workshop is purposefully vague so that everything can be canon and I get (and appreciate that) but still! I want my Legions Imperialis forces to fit into a structured order of battle and be reasonably close to what the fluff indicates a company/battalion/chapter should be. Yes, yes. I know. It's fictional and it can be anything. I also recognize that historical order of battle (i.e. WWII, WWI, etc) are fluid and the idealized force organization is idealized and doesn't necessarily represent what was actually fielded.

I'm unreasonably fixated with getting my miniature wargaming armies to fit into a structured hierarchy. I'm guessing the reason is that my first foray into miniature wargaming was with my uncle Stephen. He was a huge historical gamer (in fact, he loathed my attempt to get him to play Battletech 'cause it made no sense to him). As a result, I look at my Warhammer Horus Heresy and 40K armies in a similar way. Logistics and composition matter. Roles matter. Even if they don't really.

Before the World Eaters got their own codex - before Daemonkin of Khorne - before Slaughter cults, I was trying to force my blood soaked butchers into a structure. I was trying to compose a company sized force based upon what I had/wanted. I sketched this out (so that each squad could have their own "heraldry"):

See! Obsessed. Now, this is totally obsolete 'cause you can't have standard CSM units anymore with a World Eaters army in 40K and that's okay. I mean, it kind of changes the fluff around my army but I'm cool with that. I plan to weigh in on that later and the painting challenges that changes to valid army choices introduces but this is about something different.

Specifically... What is the __ing deal with Legion structure and why doesn't the Legions Imperialis army building rules fit nicely into what the fluff indicates? The issue, clearly is how I'm looking at it. So here's the Legion organization structure from the Legions Imperialis rule book and the first FW Horus Heresy book:

Based on this chart, a Legion company is composed of

1. A command squad: ~ 5 members
2. Detachment 1: Tactical marines/20 members; Tactical marines/20 members; Support squad/10 members
3. Detachment 2: Tactical Marines/20 members; Tactical marines/20 members; Support squad/10 members
4. Detachment 3: Tactical marines/20 members; Tactical marines/20 members; Support squad/10 members

These numbers total up to 155 elements without attached support units. Which is a bit more than the indicated 100 marines per company that's suggested in the description of a company's composition. Yeah, it says nominally and that legions tended to organize their companies (and battalions) to a higher level than they might have been at the beginning of the Crusade.

Take this as an example:

And it gets worse. The Legions Imperialis rule book's detachment rules for game play defines the order of battle at a much higher level. To field a demi-company (half a company) you're looking at the required:

1. A command unit of one base (5 members)
2. A Core at 4 bases (20) (Detachment 1)
3. A Core at 4 bases (20) (Detachment 2)

Each of these cores can be supplemented with additions of an additional 10 elements.  Terminators, special weapons (plasma or missile launcher), and assault. There's also tanks, bastion, and flyers that can be added as well as additional core tactical units. It's ridiculously easy to push a company over 100 elements.

Unless...  I take a different view. Let's take a moment to look at what a company looks like from the Legions Imperialis book (extrapolating from the demi-company). Using the 65th company of the Sons of Horus, a company has four groups let by a jr. officer. They're not called this but they're the platoons.

That would mean for a base line company:

1. Lieutenant
   Squad (20)
   Squad (20)
2. Lieutenant
   Squad (20)
   Squad (20)
3. Lieutenant
   Squad (20)
   Squad (20)
4. Lieutenant
   Squad (20)
   Squad (20)
5. Command
   Command Squad (5)
   Command Squad (5)

So that's 170 elements without additional support of any kind.  Fine. A company represents 170 line elements with support attached as appropriate for the mission and +/- based upon the composition of the Lieutenants specialization.  

I think I'm just going to have to get over it. There's no way to craft an army that is game legal and at 100 space marines. It makes me sad but... what're you going to do.